Hi,
Pl see attached file as a reference for silk screen designations. Terry slightly modified the layout to improve it. Other than that both have been tested and no issues. BTW I used 300pF caps for C2 C4 C8.
reg
Prasi
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FX8: Thanks, and questions
Prasi,
Thank you for responding. You are correct. I was posting about Still4given's copy of your layout. I used your layout to confirm what appeared to be minor defects in his.
Speaking of your layout, however, I have a few questions for you, too:
Where did C10 and C11 came from? I don't see them on Mile's original schematic, and haven't been able to spot the correction in the various posts...
Is there something against posting a Bill of Materials for FX8? I have created one, of course, but was surprised to not see one. I don't want to interfere with someone's (Apex Audio?) commercial activities, of course.
Is Q1 deliberately oriented to face Q2? If not, then wouldn't a 180 deg rotation of Q1 create several simpler routings in that area of the board?
Thx,
BF
Prasi,
Thank you for responding. You are correct. I was posting about Still4given's copy of your layout. I used your layout to confirm what appeared to be minor defects in his.
Speaking of your layout, however, I have a few questions for you, too:
Where did C10 and C11 came from? I don't see them on Mile's original schematic, and haven't been able to spot the correction in the various posts...
Is there something against posting a Bill of Materials for FX8? I have created one, of course, but was surprised to not see one. I don't want to interfere with someone's (Apex Audio?) commercial activities, of course.
Is Q1 deliberately oriented to face Q2? If not, then wouldn't a 180 deg rotation of Q1 create several simpler routings in that area of the board?
Thx,
BF
1. Its a good practice generally to locally bypass rails with elco caps, Rod Elliott recommends ( see P3). I did it for Fx-8. Also See Fx 9 schematic, Mr. Mile has incorporated those.
2. Since this is a simple circuit, one can easily read off the layout and most parts are easily available anyway, so nobody bothers with a BOM. Mr. Mile is generous enough to post his designs for us diyers. Many times he has stated, there is no commercial interest.
3. Q1 /Q2 orientation, Mr.Mile can answer that one.
Facing to each other they can easily be tied up together (to thermally couple them) using cable tie. Sometimes people use a little heat compound between the surfaces. Not a must of course.
But don't be fooled by the words "simpler routing", especially if it doesn't correlate to "proper routing".
To clarify, I also rotated Q1 for better routing (but still touching Q2) and in original Apex' PCB they are not face to face either (see attachment).
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Hi all,
Had a moment to put it on my floor-standers and listened to bollywood tracks as well as 'wish you were here' and as suspected, they sound simply amazing. After Terry, I too confirm that bass is super strong and solid along with sweet sounding mids and highs. So, Thimios, etch yourself a pair and see (listen) for yourself, you wont be disappointed and give a break for the poor little laterals (although I have to agree VSSA is a wee-bit leaner in bass region (may be my build quality, I can not comment )).
Heat sink: As soon as I tried to blast a little, heat sink started getting too hot to touch and I had to switch on fan to keep it cool. Will reduce the bias to 50-70mA and test again.
Thank you for this wonder "little" amp Mr. Mile.
reg
Prasi
disclaimer: the views presented here are totally subjective and not supported by measurements😉
Had a moment to put it on my floor-standers and listened to bollywood tracks as well as 'wish you were here' and as suspected, they sound simply amazing. After Terry, I too confirm that bass is super strong and solid along with sweet sounding mids and highs. So, Thimios, etch yourself a pair and see (listen) for yourself, you wont be disappointed and give a break for the poor little laterals (although I have to agree VSSA is a wee-bit leaner in bass region (may be my build quality, I can not comment )).
Heat sink: As soon as I tried to blast a little, heat sink started getting too hot to touch and I had to switch on fan to keep it cool. Will reduce the bias to 50-70mA and test again.
Thank you for this wonder "little" amp Mr. Mile.
reg
Prasi
disclaimer: the views presented here are totally subjective and not supported by measurements😉
Hi Prasi,
Where did the 330p come from? I don't see a schematic with those. It is stable with 100p so I'm not sure anything is to be gained by going higher.
Benz,
Good catch. I guess none of us caught it because the values are there. Makes sense that you would catch it when making a BOM. I have a very large supply of parts so I rarely fool with a BOM, especially if it is a small amp like this. I'm attaching an updated silk.
Edit: I am including a file for Thimios
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Hi Terry,
It was on Mr. Mile's layout. Post #6174 http://www.diyaudio.com/forums/soli...imate-fidelity-amplifier-618.html#post4605393
reg
Prasi
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I am/was confused what you were asking regarding the 330p, because I knew about it the first time from your post above. You might be asking something else I don't know...
Matter? May be a little. Very little. Terry had mentioned the issue with HF and that it is still okay with 100pF. I prefer to keep no more than 100pF between driver's collector and base. The input filter is okay with bigger capacitance.